URGENT...engine advice needed!

[Dickieboy]

Could I just be permitted to say that I have learned more about my GS by reading the threads in this post than in my preceding 3 and a bit years of ownership, I hope you are able to sort your bike out and continue your journey.

And thank you to the site members for helping my education re my GS priceless

 

[acerimmer]

Could it be a split fuel pipe coming out of the fuel pump?

That was a problem on my bike, (1150gs) every time the throttle was opened wide the bike would bog down, the fuel that should have gone to the injectors was just pushed out of the split pipe and back into the tank.

Good luck with the rest of your trip anyway.

 

[skywalker]

don't know if you've got a multimeter with you Simon, but i'd check the injectors valves. Pull off the electrical connector on each one & measure across the 2 pins onthe injectors.You should be getting a reading of between 15 to 16 kohms -anything less than 15 suggests a faulty injector valve which will give you the symptoms you have mentioned

 

[Vern]

Oi,Tosser,have you mended it yet??If you haven't,throw a match on it,at least you'll be warm then

I'll get me coat

 

[Steph]

hi Simon

Sorry to hear about your troubles! there are some really good points above... Do you still have the little device i gave you to check the blink codes on your engine controller - with the text... if so, it willl take you a couple of minutes to read the fault codes and see (at least wheather the ECU thinks there is something wrong - if so, it will give us a better idea, if not, we know to look to external influances...)

in case you don't have it anymore... look at the following
found a dutch link:
http://www.bmwgsclub.nl/motronic-reset.html
oterh useful pictures:
http://www.bmwgsclub.nl/motronic.html
Ahhh the German one i once showed you:
http://www.triebel-tuning.de/elektronik/seiten/auslesen_des_fehlerspeichers_mot.htm

Remember 2 things:
a) if you dont crank the engine before checking the codes you will always find the Hall sensor codes present (1122 and 1133) (if you haven't cranked the engine, that's ok)
b) if you have removed the power to the ECU recently, i.e fuse 5 as suggested above, you will have lost the current fault codes - don't dispair they will reappear (eventually) if the fault hasn't been fixed yet.. - will just take some time...

- I'm sure the pictures will refresh your memory - If any of you kind folks have this in English to make Simon's life easier - it would be much appreciated...

if you don't have the little device anymore ;-) we canmake one with what you have with you.. I know you alwas carry spage light bulbs and Lisa can lend two extra hands...
Below I follow the German example (see the difference between German one and Dutch one is that they connect the light (bulb or LED) from Pin1 to Battery negative (Dutch example) or Battery Positve (German example) - the lights will just be inverted... - you're smart you'll see that!!!

1. Connect any 12v bulb between Battery Positive and Pin1 on the diagnostic plug. Keep an extra wire connected to Pin1 with the other end free - we will later use this in place of the push button on the pictures...
2. Start the motor,
3. with the bulb connnected as in (1), use the end of the spare wire and short it to battery negative for 5 seconds (this shorts pin1 to battery negative and telles the ecu to send its first fault code
4. after releasing the spare wire from negative, count the pulses... fault codes are made up of 4 digits, and digits are seperated by longer pulses...
Once the number repeats, you can repeat step (3) -this will trigger the next code...
5. repeat until 4444 or 0000

now for the codes - will try my best in English
4444 No Faults in memory
4445 CO2 potentiometer
1122 Hall sensor 1
1133 Hall sensor 2
1215 TPS sensor
1223 Oil temp sensor
1224 Air temp sensor
2341 Lambda sensor at limit
2342 Lambda sensor value implausible
2343 Mixture ratio limit reached
2344 Lambda sensor shorted to Battery negative (-)
2345 Lambda sensor shorted to 12V
0000 No further faults in memory

Remember the Fault codes are not the Beginning and end of everything - especially with the old controllers like the MA2.2 however it's worthwhile to take the 5 minutes and check what it thinks could be wrong - if at all it finds something wrong...

Looking at the Fault codes they don't say a lot, especially taking into account ath you don't have a lombda sensor anymore.... However give it a try.... if you do find anything , it can just help....

My best wishes, and pls let us know what you find, then we can combine all our knowledge to furthre help you...

My best to Lisa!

your friend
Steph

 

[Steph]

hi Simon,

Spoke to a great Tech today! - He sends his best

He suggests to look at the Fuel pressure regulator as well... - situated under your battery compartment.

It might be blocked - Sure, but that would lead to less fuel I immediately thought... exept if the fuel return is blocked... the fuel pressure reg opens a valve once certain pressure is achieved (by the elec fuel pump) - this valve passes excess fuel back into the tank... in so doing keeping your fuel pressure at a stable level. Hence if it is blocked you will have raised fuel pressure, leading to (possibly huge) overfueling... - especially under load...

Ok, so how do you test it... hmmm - unless you can blow 2.5 or 3 bar (or whatever it is - I don't know ... HOWEVER, what you could try is to swop the two fuel lines from the tank (this would reverse the flow through the pressure reg and possibly clean it out if some gunk was blocking the return path...

Pls let us know how things are progressing... (Don't have any nails left)

cheers
Steph

 

[simon thomas]

thanks for all the advice guys. Steph..cheers mate. Yes I do still have the blink code tester. I´ll give it a go tomorrow.

We´ve just reached Potosi yesterday after coming through the atiplana and the Solar de Ayuni. I´ve now got a chance to look at the bike again.

Before we left Chile i did replace all the fuel lines inside the tank incase of splits and blew out the fuel filter etc, etc. This did seem to help.

We spent the entire day riding corrugations from Ayuni to Potosi and what should have been a great ride turned to pure frustration. Here´s the problem.

Under moderate acceleration the bike is feeling better, but as soon as the bike is vibrated ie. riding over corrugations or rocks the engine simply splutters, and looses power to the point where I have to change down gear. Bouncing bike equels spluttering power dive. Help??????

Does this new symptom point to anyone of the suggestions already made?

Any advice would be great.

Best wishes
Simon Thomas

 

[RadioActive]

If vibrations makes it worse then I guess it could be the earthing problem somebody mentioned, or some other poor electrical contact. Good luck.

Chris

 

[(RIP) Kaister]

Before we left Chile i did replace all the fuel lines inside the tank incase of splits and blew out the fuel filter etc, etc. This did seem to help.

Could be the fuel pump going bad - or the wiring to it - or the fuse connection corroded etc.

Have Fun

 

[Duncan Richmond]

Hi Simon,

As Timolgra suggested, have you changed the H.T. leads yt (assuming you have spares) I had a similar problem with my airhead when I was in India - ponced around for ages striping carbs, changing plugs, checking wiring only to find that one of the H.T. leads had an internal fracture.

Good luck

Duncan

 

[RickG]

Hi,

Just some more thoughts to be going on with:

Power loss/misfire under sustained heavy load can be caused by too rich a mixture. The possible causes have been mentioned by previous posters but the sooty exhaust does point to this. If it's both cylinders then you are looking, as suggested, at temperature sensor problems; is the bike ok when the engine is cold? If so a temp sensor failure is a strong possibility. If not then over pressure may be a problem from a failed/failing fuel pressure reg'.
Sitting up there 2 miles in the sky with no air will not help at all.

I'd expect a failing fuel pump to make it run weak, not rich.

If only one cylinder is sooty it's more likely to be a leaking injector on that side only

Having gone down the route of over rich, clearly over-lean will cause misfire. I had a an 1150 with only 10k on the clock that had a misfire from a clogged fuel filter. It kind of gasped and stumbled when the throttle was whacked open. A split in your pipes or failing fuel pump will lower the fuel pressure to the injectors and could cause the same problem, particularly when you need loads of juice, ie susutained big throttle openings.

Obviously you need to be sure if the thing is over rich or over lean as this will be key to the diagnosis

Misfire under load can also be caused by a failing a failing HT sytem (it's harder for the spark to jump the gap at high cylinder pressures as opposed to low ones at light load) Check both the leads, plug caps (the inbuilt resistor can crack) and remove any muck that may cause the spark to track back under the cap to earth. Prolonged electrical misfire will aslo lead to sooty deposits from unburnt fuel

The fact that it's worse with vibration does point to intermittent mechanical failure of a component, whether this be a poor electrical connector, cable, sensor or fuel pump

I can't see a failing butterfly valve causing the problem at large openings as all you will get is a bit of an air leak which will make that cylinder run a bit weak

Anyroad, good luck. I hope you can get it sorted. If it's any consolation, although my bike is running Ok I've got a lousy view and it's raining again.